#include<stdio.h>
int main()
{  signed int a;
   unsigned int b,c;//这是无符号整型用%u输出
   c=10;
   b=-10;//这是无符号整型但赋值让其转化成有符号整型所以继续用%u输出会达到上限值；
   a=-10;
   printf("%d\n",a);
   printf("%d\n",b);
   printf("%u\n",b);
   printf("%u\n",c);
   return 0;
}